Then Herewini stepped up.
A minute before the end of the third quarter, he broke down the right, dribbled along the baseline and flicked the ball over Canterbury goalkeeper George Enerson for a terrific individual goal. He then sealed the win two minutes from the end with a turn, swivel and hard drive into the Canterbury goal in the final quarter, celebrating by slamming his stick into the turf.
In the women's K Cup final, Canterbury came out firing and opened the scoring in the 11th minute when Olivia Merry went on a solo run before firing an amazing shot into the net past the shoulder of goalkeeper Brooke Roberts.
The Cats doubled their lead 10 minutes later when Joie Leigh capitalised on a bobbling ball from a penalty corner deflection and knocked into goal.
North Harbour struck back through Stephanie Elliot from a 27th-minute penalty corner before Canterbury netted again right on halftime from the stick of Jenny Storey.
Harbour lifted the intensity after the break and cut Canterbury's lead to one goal after Stephanie Dickins struck from a 46th-minute penalty corner deflection.
Canterbury's steeled themselves on defence in the final quarter and kept North Harbour from scoring an equalising goal despite huge pressure.
Canterbury captain Jenny Storey was named Most Valuable Player and Midlands striker Amy Robinson finished top goal scorer having netted five times during the tournament.
Central took third spot in the men's competition, beating North Harbour 3-2 in a penalty shootout after the sides had finished 3-3.
Capital beat Auckland in a goal bonanza, 6-4, to decide fifth and sixth places. Black Sticks attacker Stephen Jenness scored three times for Capital. That completed a miserable tournament for defending champions Auckland.
Midlands won the bronze in the K Cup, beating Auckland 2-1, while Capital beat Northland 3-2 in another shootout, after the fifth-sixth playoff finished 1-1.